Various studies have been previously made for a system for controlling power. As such power control systems, there are, for example, an HEMS (Home Energy Management System) for controlling power in a home, a BEMS (Building Energy Management System) for controlling power in a building, and a CEMS (Community/City Energy Management System) for controlling power in an area such as a municipality. The objective of those power control system is for forming a sustainable society by bringing efficiency to use of power or by actively using nature originated energy (solar light, wind power, geothermal heat, or the like). Hitherto, power control means power control at supply side such as power plants.
However, with rise of energy management systems, in recent years, there is an active move afoot to carry out power control at demand side. This is called a “demand side management”. There are several types of the demand side management. By way of illustration, as the demand side management, there are one for controlling power demand geared toward for a small free as much as possible in response to a dynamic placing so as to change the cost of power hourly and another for controlling power demand in order to ward off failure such as a power failure by cutting a peak upon power demand peak. As a concrete example of the latter, a power-saving request is made for the building when demand for power tightens. That is, power which each building may use at an upper limit (which will later be called an “upper limit power”) is notified. It is touted for each building to restrain within the notified upper limit power.
It is conceivable that a request to wish to control demand for the upper limit power become large in future. This is because policy and popular mandate move from conventional trend in which power may be used as you can use in the direction of skillfully using limited power. To enlarge power plants in agreement with demand is impossible in policy and it is said that the occurrence of demand which may outstrip the total amount of generation of electric power in the power plants is on the order of several days throughout the year. Under the circumstances, it is reasonable to control the demand side than making the supply side power-up. In addition, the demand control is also important in crisis management because it may not make a simultaneously planned power cut if the demand is flexibly controlled on occurrence of disaster.
Under these circumstances, studies for making the demand control for the upper limit power have been carried out. A method carried out in a current BEMS is a method: of preliminarily laying down a plan whether or not respective devices (air conditioners, light fixtures, elevators, and so on) in the building are stopped on a power-saving request; and of stopping, in response to the power-saving request, the preliminarily planed devices in agreement with the upper limit power. Although it is understood that the demand control can be easily carried out if doing in this manner, but whether or not it is comfort for people in the building is another story.
There are devices whose power cannot be controlled in the building. For example, in the building in which business facility is combined in one unit, it is to be wished that it does not conserve electricity devices in the business facility. This is because customers leave if a power savings so that the customers think unpleasant is carried out. In such a case, the devices in the business facility are dealt with as outside of power controlled objects. In this event, inasmuch as power used in the business facility always changes, the demand control is carried out so as to estimate the maximum amount of power used in the business facility in expectation of safety and to stop the devices. It falls into the situation where the power-saving is continued to excess in a floor on which the devices are controlled even if the business facility does not use the maximum amount of power. In a word, although the power-saving request is satisfied, it results in the power-saving in which people in the building endure because the power-saving is made more than necessary. In addition to this, there is a case where devices which are not planned to stop are turned off, it therefore results in the extra power-saving including portion of such devices.
Not only the above-mentioned example, the current demand control preliminarily makes a study of a forecast for demand and supply and of a plan when the devices are used or are stopped, and carries out control in keeping with the plan. In a case of such a control, it results in the power-saving with a margin more than necessary because the preliminarily made plan may come off and the devices in which power cannot be controlled in the manner as the above-mentioned example are expected. In order to make people which live and work at this place spend comfortably to the maximum, a technique to control power of the devices as circumstances demand is necessary by comparing the upper limit power and the total of current used power without the preliminarily determined plan.
Various prior art documents related to this invention are known.
For example, JP-A-HEI11-178247 (Patent Literature 1) discloses a “power consumption management system” which comprises: holding a value of a maximum permissible power consumption based on a value of a contract power for an electric utility; comparing a total value of power consumption of all devices with the value of the maximum permissible power consumption; notifying a centralized control office of information of an ambient temperature and so on; and controlling the power consumption of the respective devices.
In addition, JP-A-2004-145396 (Patent Literature 2) discloses an “electric power transaction management method” which comprises: deriving, using Ito's lemma, a stochastic process following price in a case where demand makes the geometric Brownian movement on the assumption that there is a determined functional relationship between power demand and power price; and deriving, using no decision principle, a differential equation for dominating price of derivative securities written on such a stochastic process.
JP-A-2005-341646 (Patent Literature 3) discloses an “energy saving system” which comprises: managing control priority information for determining which energy device should be preferentially controlled; and controlling energy suppression of the devices in order of decreasing priority.
In addition, JP-A-2006-74952 (Patent Literature 4) discloses an “electric power peak-off control system” which comprises: comparing a reported reduced amount of electric power with a reduced amount of electric power after being controlled and measured; and comparatively determining the value so as to reach the reduced amount of electric power thereby carrying out reduction of electric power peak.
Furthermore, JP-A-2010-124605 (Patent Literature 5) discloses a “power consumption prediction device” which comprises: comparing among power consumption data to apply an evaluation function; and extracting power consumption data having a high correlation value from actual data.
JP-A-2010-146387 (Patent Literature 6) discloses an “energy saving behavior evaluating apparatus” in which an energy saving behavior evaluation part acquires data in yesterday or last week from an appliance information database to evaluate them using an evaluation function, and records an evaluated value in an evaluated result database.
WO2012/160978 (Patent Literature 7) discloses an invention relating to a method comprising of autonomously and dispersively controlling a plurality of devices and of carrying out optimal load dispersion on the whole.